Fans



June 27, 1967 N. LAING 3,327,934

FANS

Filed March 18, 1966 e Sheets-Sheet 1 INVENTOR- ATTO R NE YS June 27, 1967 N. LAING 3,327,934

FANS I Filed March 18, 1966 6 Sheets-Sheet 2 INVENTOR Nikolaus Loin WM, saw-2 A'TORNEYS June 27, 1967 N. LAING 3,327,934

FANS

Filed March 18, 1966 6 Sheets-Sheet 3 m w f/fa w #42 m INVENTOR WNikoluus Lain W, 7 7"'AT T oRNEY;

June 21, 1967 N. LAING 3,327,934

FANS

Filed March 18, 1966 v 6 Sheets-Sheet 4 F/GJO.

'F/Gfi. F/G.72.

F/GJ3.

m 5 M7 i w 5 INVENTOR ikolgus Loin 5' I flTTRNEY June 27, 1967 N. LAING mus Filed March 18, 1966 6 Sheets-Sheet 6 FIG.6.

INVENTOR )hkolu us Lou H ATTORNEYS United States Patent 14 Claims. 61. 230-425 This application is a continuation-in-part of my copending application 427,429, filed Jan. 22, 1965, now Patent No. 3,241,724, itself a continuation-in-part of application 95,405, filed Mar. 13, 1961 and now abandoned.

This invention relates to fans of the cross-flow type, more especially though not exclusively for domestic purposes. A fan of the cross-flow type comprises a cylindrical bladed rotor mounted for rotation about its axis in a predetermined direction and defining an interior space, and guide means defining with the rotor a suction region and a pressure region, the guide means and rotor co-operating on rotation of the latter in said predetermined direction to induce a flow of air from the suction region through the path of the rotating glades of the rotor to said interior space and thence again through the path of said rotating blades to the discharge region. More especially but not exclusively the invention concerns fans of the cross-flow type wherein the guide means and rotor co-operate to set up a vortex of Rankine character having a core region eccentric of the rotor axis and a field region which guides the air so that flow through the rotor is strongly curved about the vortex core: such a fan will herein be designated a tangential fan.

Fans of the cross-flow type are well adapted for domestic use since they can be made relatively small and quiet, and by using an appropriate length of rotor can be designed with an outlet of any desired long rectangular cross section. Cross-flow fans can be used as table fans, and can be incorporated in hoods for use in kitchens or in extractor or two way fans such as may be built into a wall or window aperture.

In some domestic applications the rotor of a cross-flow fan can become fouled with dirt or grease to an extent that the efficiency of the fan is gravely impaired. From the manufacturing point of view it is often advantageous to make the rotor of plastics material; however this aggravates the problem of fouling, since a plastics rotor tends to pick up dust and dirt by electrostatic attraction. The rotor for a cross-flow fan is commonly closed at its ends and has close-set blades, which makes it difiicult to clean in situ, especially as the adjacent guide means and other parts prevents ready access to the rotor.

The main object of the invention is to alleviate the problem above discussed. According to the invention the means mounting and transmitting drive to the rotor from a drive shaft therefor comprise coupling elements respectively at the shaft and at the adjacent end of the rotor which coupling elements are capable of separation and reassembly by manual manipulation and on reassembly co-operate to centre the rotor on the axis of intended rotation. This arrangement enables the rotor to be readily removed for cleaning and reassembled thereafter, without the aid of tools. Once removed the rotor can be washed and tedious cleaning procedures avoided.

The invention can be applied both to cross-flow fans where the rotor is overhung on the drive shaft and to fans where the rotor is supported at both ends.

An overhung rotor can be mounted according to the invention, in various ways. Provided the drive shaft can be gripped to stop it from turning, the rotor may screw on to it against a shoulder. Alternatively the shaft may terminate in a tubular end portion; the coupling element on the rotor may then comprise a tubular part to engage 3,327,934 Patented June 27, 1967 over the shaft end portions and a resilient retainer portion in frictional engagement within the shaft end portion. Yet another coupling method is to have the coupling elements as ferro-magnetic discs engaging face-to-face, at least one disc being permanently magnetized, and one element has a conical projection received in a centring recess in the other element. In a further embodiment of the invention, particularly suitable for a plastics rotor construction, the coupling element at the shaft includes a disc with a shoulder and the coupling element at the rotor includes an end ring, the disc and ring having co-operating means for snapping the ring into retaining engagement over the disc and into abutment with the shoulder.

In application of the invention to a rotor supported at both ends, the rotor mounting means includes a bearing at the end of the rotor opposite the drive shaft: preferably this bearing is movable between an operative position aligned with the shaft axis and a second position laterally spaced therefrom for disengagement of the rotor from said bearing. The coupling elements can conveniently include part-spherical surfaces which with the bearing in operative position are held in interengagement by reason of endwise location of the rotor by said hearing; this location can be effected with the aid of an endwise bias on the hearing. A preferred form of bearing comprises a pin or the like engaging in a recess in the non-driven end of the rotor. This arrangement enables self-alignment and can be designed for low friction and low wear: also, it can readily absorb the desired endwise biassing force.

Further features of the invention will appear from the following description of various embodiments thereof given by way of example with reference to the accompanying somewhat diagrammatic drawings, in which:

FIGURE 1 is a view of a first form of tangential" fan according to the invention where the rotor is supported at both ends and readily manually detachable without the aid of tools, the view being taken facing the non-driven end of the rotor;

FIGURE 2, is a longitudinal vertical cross section through the fan, with the motor shown in outline;

FIGURE 3 is a longitudinal horizontal cross section of the fan, with the motor omitted;

FIGURE 4 is a perspective view of the fan seen from the suction side, with part cut-away, the view being taken with the rotor in position for removal;

FIGURE 5 is a partial view of a modified form of the tangential fan of FIGURES 1 to 4, the view being taken facing the non-driven end of the rotor with portions in section;

FIGURE 6 is a partial longitudinal sectional view of a further modification of the fan of FIGURES 1 to 4;

FIGURE 7 is a longitudinal sectional view with parts omitted, of a tangential fan, the motor being shown in outline, the rotor in this case being supported at the driven end only, and readily detachable manually, without the aid of tools;

FIGURES 8 and 8a are respectively a cross-sectional and a longitudinal sectional view, with the motor shown in outline, of a tangential fan having two rotors overhung mounted on the opposite ends of the motor shaft, both being readily detachable manually without the aid of tools;

FIGURES 9a, 9b and 9c are longitudinal section views showing three ways of mounting a rotor in an arrangement such as that of FIGURES 8 and 8a;

FIGURE 10 is a longitudinal sectional view of a tangential fan with an overhung mounted rotor mounted magnetically for ready manual removal without the aid of tools;

FIGURE 10a is a perspective view of the casing for the FIGURE 10 fan;

FIGURES 11 and 12 illustrate different forms of magnetiz'ation for removably mounting the rotor in the FIG- URE 10 fan;

FIGURE 13 is a partial longitudinal section showing yet another method of magnetically mounting a rotor upon a shaft for ready removal, and

FIGURE 14 illustrates yet further means for detachably supporting a rotor in overhung relation on a motor shaft.

The tangential fan illustrated in FIGURES l to 4 comprises generally parallel end walls 1, 2 interconnected by a pair of guide walls 3, 4 to form a rigid structure. An electric motor 5 having a driving shaft 6 is mounted on one end wall 1. A bladed cylindrical rotor 7, comprising a series of similar closely spaced blades 8 arranged in a ring around the rotor axis and extending parallel thereto between end support discs 9, 10, is supported for rotation upon the motor shaft 6 at one end and upon a bearing assembly designated generally 11 at the other end, with the rotor axis coinciding with the axis of rotation defined by shaft axis. A disc 12 (FIG- URES 2 and 3) is fixed on the end of the motor shaft 6 by means of a hub 13 and has a peripheral portion 14 of part-spherical shape. The adjacent end disc 9 is of similar part-spherical shape and abuts the peripheral part-spherical portion 14 of the disc 12 in frictional area engagement under endwise pressure due to a biassing spring 15 acting on the bearing assembly 11, as will be described. The engaging part-spherical surfaces have a common centre 0 (FIGURE 3) on the axis of rotation. The disc 12 on the motor shaft 6 and the end disc 9* of the rotor form coupling elements which support the driven end of the rotor 7 and transmit drive thereto.

The bearing assembly 11 comprises a first element in the form of a boss on the end disc 10 of the rotor and defining a conical axial recess 21, and a second element in the form of an axially disposed pin 22 with a rounded end engaging in the recess 21 under the influence of the biassing spring 15. The pin 22 is mounted for longitudinal sliding movement in a bore 23 of an arm 24 which is pivoted to the end wall 2 by means of a pin 25. The arm 24 has a recess 26 which receives the boss 21 with clearance. The spring 15 is of leaf type with one end riveted to the arm 24 at 27 and the other acting on the outer end of the pin 22, which is flanged at 28. A second leaf spring 29 (FIGURES 1 and 4) secured to a bracket 30 on the end wall 2 has a cranked end 31 engaging in a notch 32 at the top of the arm 24.

In the operative position of the rotor 7 as just described, the rotor co-operates, on rotation by the motor in the direction of the arrow 35 (FIGURE 1) with the guide walls 3, 4 to induce a flow of air from a suction side S of the rotor, through the path of the rotating blades to the interior thereof and thence again through the path of the rotating blades to a discharge side D. Flow takes place generally in planes perpendicular to the rotor axis as, indicated diagrammatically in FIGURE 1 by the flow lines F. A fuller description of how flow takes place in a tangential fan as here shown is given in my Patent No. 3,232,522.

The arm 24 forms part of a bell-crank lever desig nated generally and having a second arm 41 terminating in a finger rest 42. By manual manipulation of the arm 41 the lever 40 can be moved between the operative position above described where the bearing pin 22 is located on the axis of rotation by the aid of the locating spring 29, and a second position where the arm 41 rests against a stop 43. In FIGURES 1 and 3 the operative position of the lever 40 is indicated in full lines and its second position is shown in chain lines. In FIG- URE 4, the lever 40* s shown in full lines in its second position. As the lever 40 is moved from the operative to the second position the non-driven end of the rotor 7 is shifted laterally by the bearing assembly 11, the partspherical surface of the rotor end disc 9 sliding over the corresponding surface of the disc 12. After a certain movement the pin 22 disengages from the recess 21 in the rotor end boss 26, and the latter is retained in the oversize recess 26 until, with the arm 41 against the stop 43, the rotor 7 is just released and rests on a projection 44 formed on the guide wall 3. The rotor 7 may then be removed completely for cleaning. To reassemble the rotor it suffices to engage the end disc 9 over the disc 12 on the motor shaft and enter the rotor end boss 20 in the oversize recess 26 in the arm 24. On manipulation of the lever arm 41 towards the operative position the pin 22 automatically re-engages in the recess 21, and the rotor end disc 9 slides over the disc 12 and is automatically centred thereby. Finally the locating spring 29 snaps into the notch 32 to retain the parts in operative position until it should once again be necessary to clean the rotor.

It will be noted that end wall 2 is formed with a cutout 45 (FIGURE 1) permitting the lateral movement of the rotor above referred to. Guide wall 4 is formed with a recess 46 accommodating the disc 12 and its hub 13, and providing also room for the rotor end disc 9 to slide around the disc 12 as the rotor is removed (see especially FIGURE 3).

FIGURE 5 shows a modification of the construction described with reference to the previous figures, where the portion of the upper part of the lever arm 24 is cut away to provide a side opening 50 into the recess 26. This enables the rotor to he slid out sideways by hand, even while the boss 20 on the rotor end plate is still supported within the recess.

FIGURE 6 shows a further modification of the fan illusstrated in FIGURES 1 to 4, wherein the bell crank lever 40 is omitted and the bearing assembly here designated 11 comprises a ball bearing 51 held captive within a tubular projection 52 from a recessed portion 53 of the end wall 2. The ball 51 is urged by a spring 54 into a recess 55 in the rotor end wall 10. In the operative position shown, the non-driven end of the rotor is supported for rotation upon the ball 51. When it is desired to remove the rotor, the non-driven end of it is shifted laterally. The ball then rides out of its seat 55 against pressure of the spring 54, while the part spherical disc 9 at the driven end of the rotor slides over the part spherical surface of the supporting disc 12, as previously described. For reassembly of the rotor it suffices to engage the end disc 9 over the supporting disc 12, with the rotor at an angle to the axis of rotation. The non-driven end is then moved until approximately in alignment with the rotational axis, whereupon the ball 51 will find the recess 55 and enter it under pressure from the spring 54, to effect final alignment.

FIGURE 7 illustrates a tangential fan having a rotor 60 which is overhung mounted on the end of a shaft 61 of an electric motor 62. The shaft end portion 63 is tubular. The rotor has an end disc 64 with a tubular projection 65 fitting snugly over the shaft end portion 63. The rotor also carries, inwardly of the disc 64, a second disc 66 of spring material having a split projecting retainer element 67 which resiliently engages within the tubular end portion 63 of the shaft 61. The disc 64 includes an axially directed flange 68 embracing the rotor and helping to keep it in proper alignment.

Alternatively, the disc 64 may be fixed to the shaft end portion 63, the rotor then comprising simply the disc 66 to which the blades are attached. In this arrangement the rotor is assembled by entering the split projection 67 within the tubular shaft portion 63 until the rotor end disc 66 abuts the fixed disc 64 and lies within and snugly surrounded by the flange 68.

It will be understood that the rotor 60 in FIGURE 7 can readily be removed manually from the motor shaft and reassembled therein, without the aid of tools. The guide Walls and support structure are not shown in FIG- URE 7, but may have the same form and function in the same manner as described with reference to FIGURES 1 to 4.

The room fan unit shown in FIGURES 8 and 8a comprises a base 101 supported upon legs 102 a housing 103 wherein is located a motor. The motor is of conventional type and not shown and the housing is indicated simply as a block having an upper wall 103a of substantial thickness. The motor has a horizontal spindle and the two end portions of the spindle designated 104, 104, extend symmetrically from the housing at either end thereof. Each end portion 104, 104', of the spindle is formed with a flange 105, 105' spaced from its end, which end is formed as a threaded stub 106, 106'. A pair of similar cylindrical bladed rotors 107, 107' are mounted on the end portions 104, 104 of the spindle. Each rotor comprises end discs 110, 111 supporting between them a series of blades 112, and the end disc 111 has'a tapped axial hole enabling it to be screwed upon the corresponding threaded stub 106, 106 until it comes flat against the flange 105, 105.

The fan unit further comprises a guide unit 103 having two similar sections 113w, 113b, each section co-operating with one of the rotors 107, 107. The guide unit sections 113a, 1115b are connected by an integral central portion 113a which overlies the housing 103 and is secured thereto by a milled-headed screw 114 working in a tapped hole in the wall 103a of the housing.

Each guide unit section 113a, 113b provides a pair of approximately crescent-shaped end walls 115, 116 respectively coplanar with the rotor end discs 110, 111 and joined by guide walls 117, 118. As seen in FIGURE 8 the guide wall 117 is short and converges with the periphery of the rotor 107 in the direction of rotor rotation indicated by the arrow 120 in FIGURE 8. The line 118a of nearest approach of the guide wall 118 to the rotor 107 lies approximately diametrally opposite the line 117a of nearest approach of the guide wall 117. At both lines 117a and 1118a the respective guide walls 117, 118 are spaced from the rotor substantially more than a working clearance, preferably about half the radial blade depth, or possibly more. The Wall 118 extends away from the rotor 107 with a steady increase in radius of curvature going from the line 118 a. Guide walls 117 and 118 terminate remote from the rotor in lines 117b, 118b which define the outlet from the unit, for the rotor 107. The plane joining the lines 117b, 1181: is oblique to the direction of flow through the outlet.

The-blades 112 of the rotor 107 will be seen to be concave facingthe direction of rotation and to have their outer edges leading their inner edges.

In operation of the unit a cylindrical vortex having a core shown by the flow lines V is formed adjacent to guide wall 117: the vortex core intersects the blades and lies parallel and eccentric to the axis of the rotor. Air is induced to flow through the rotor as shown by the flow lines F. The principles upon which the fan unit of FIGURES 8 and 80 operates are set forth in detail in the British patent specifications 876,611 which should he referred to.

The flow machine of FIGURES 8 and 8a can readily be disassembled for cleaning without the use of tools by simply unscrewing the rotors 107, 107 from their threaded stubs 106, 106 and removing the guide unit 113 after unscrewing the milled-headed screw 114. The rotors 107, 107' and guide unit 113 can conveniently be moulded of plastics material.

Three further ways of detachably securing a rotor to a driving shaft, in an arrangement such as that of FIG- URES 8 and 8a, are shown in FIGURES 9a, 9b and 9c. In FIGURE 9a, a circular retainer plate 130 of greater diameter than the rotor 107 is formed on the end of the shaft portion in place of the flange 105 of FIGURE 8a. The adjacent end disc 111' of the rotor 107 differs from the end disc 111 of FIGURE 8a in carrying a threaded projecting boss 131 co-operating with female threads 132 formed axially of the retainer plate 130. The plate 130 and rotor 109 can readily be grasped in the hands when it is desired to separate them: this arrangement is therefore particularly suitable where the construction of FIG- URES 8 and 8a is modified to present only one rotor.

FIGURES 9b and show rotors 107 detachable by snap action. In FIGURE 9b the shaft end portion 104 is shown terminating beyond the flange in a cylindrical boss 133 formed with a transverse bore 133a locating a pair of balls 134 urged outwardly by a helical compression spring 135 acting between them, the balls being prevented from flying out of the bore by lips 133b formed at its mouth. The rotor end disc 111 is formed with a bore 111a receiving the boss 133 in a close fit, and a groove 1111: opening out of the bore. The balls 134 are received in the groove 11111; the rotor can readily be assembled and disassembled simply by exerting a pronounced axial force thereon. Drive from the shaft 104 to the rotor 107 is effected by friction, bearing in mind that only low torques are involved. Alternatively co-operating flats may be formed on the boss 133 and end disc 111, or a projection on the flange 105 may engage a recess in the end disc.

Parts of the FIGURE 90 construction similar to that of FIGURE 9b are given the same reference numerals and will not need further description. Instead of the transverse bore 133a of FIGURE 9b, the boss 133 of FIG- URE 9c has a peripheral groove 136 locating a toroidally wound resilient strip 137. Once again assembly and disassembly is effected by pronounced axial force such as can readily be applied manually without the aid of tools.

The fan unit of FIGURES 10 and 10a comprises a base 140, a supporting post 141 upstanding from the base and mounting a motor housing 142 in the form of a cylinder with a closed end, and guide means designated generally 143 which extends to one end of the motor housing. The parts so far mentioned are all moulded integrally from plastics material by means of a four-part mould, one part of which is stationary and the other parts of which move in three directions at right angles to one another when it is required to release a completed article from the mould, the article finally being stripped from the stationary part. After moulding, a strip of plastics material 144 is secured across the guide means 143, e.g. by adhesive; thereafter the parts appear as shown in FIGURE 10a.

A motor 145 is push-fitted into the housing 142 and retained therein by friction. The motor has a shaft 146 mounting a magnetic disc 147 in line with the opening in the housing 142, this disc having a central conical centering projection 148. A rotor designated generally 149 and having end discs 150, 151 supporting blades 152 be tween them is mounted on the magnetic disc 147, the end disc 151 for this purpose being made of magnetic material and having a recess 152 co-operating with the centering projection 148.

The rotor 149, apart from the end disc 151, resem bles the rotor 107 in FIGURES 8 and 8a. The guide means 143 provides end walls 153, 154 similar to the end walls 115, 116 of FIGURES 8 and 8a, and a guide wall 155 similar to the guide wall 118 of those figures. The strip 144 corresponds in function to the guide wall 117 of FIGURES 8 and 8a. The flow conditions in the FIGURE 10 fan unit are therefore exactly similar to those illustrated in FIGURE 8, and will require no further description.

The discs 147 and 151 can be magnetized in various ways: as shown in FIGURE 11 annular zones can be formed, the zones, going radially, alternating in polarity. Alternatively, as shown in FIGURE 12 the zones can be sector-shaped. In the FIGURE 13 arrangement the disc designated generally 147 is formed as a magnetized block of cylindrical shape associated with a magnetic disc 171 having an axially directed peripheral flange 172: the rotor disc 151 is ferromagnetic, and magnetic circuits are set up in radial planes the flux wherein tends to hold the disc 151 up to the disc 147.

To disassemble the fan unit illustrated it suffices to exert an axial pull on the rotor 149 to overcome the magnetic forces set up between the discs 147 and 151; the rotor can then be washed if desired and the interior of the guide means 143 becomes accessible for cleaning. The motor 145 can be removed by exerting pressure on the end 175 of the shaft 146 opposite the disc 147: this end 175 of the shaft projects into a small hole 176 in the end wall of the motor housing 142. Once the motor 145 is out of the housing 142, the unit consisting of base 140, post 141, housing 142 and guide means 143 can be washed.

A further method of detachably securing a rotor to a shaft is shown in FIGURE 14. The rotor, designated generally 180, is made of resilient plastics material and comprises blades 181 extending between a disc 182 at one end and a ring 183 at the other. The ring 183 has its inner periphery bevelled slightly. The shaft 184 mounts a disc 185 of resilient plastics material the periphery of which is also slightly bevelled, and the disc 185 carries a stepped-back flange 186 that extends radially. The means diameter of the inner periphery of the ring 183 is the same as the means diameter of the disc 185, but because of their being bevelled their opposing edges 183a, 185a interfere. On account of the resiliency of the plastics these edges 183a, 185a can be forced past each other with a snap action and will thereafter interengage to hold the ring 183 tight against the flange 186.

I claim:

1. A fan comprising a drive shaft, a bladed cylindrical rotor, means mounting the rotor for rotation about an axis coincident with that of the drive shaft and for transmitting drive from the shaft to one end of the rotor, guide means co-operating with the rotor whereby on rotation thereof in a predetermined direction by the drive shaft to induce a flow of air from one side of the rotor through the path of the rotating blades to the interior of the rotor and thence again through the path of the rotation blades to another side of the rotor, said mounting and drive transmitting means including coupling elements respectively at the shaft and at said one end of the rotor and a bearing assembly at the other end of the rotor including a first element on said other end of the rotor and a second element mounted for movement with respect to the guide means between an operative position on said axis wherein said elements co-operate to support and axially locate the rotor for rotation by the drive shaft and a second position laterally spaced from the operative position wherein the first element and second elements disengage, the coupling elements accommodating movement of the rotor consequent upon movement of the bearing assembly element between said operative and said second position thereof and being capable of separation and re-assembly on manual manipulation of the rotor with the bearing assembly elements in said second position, and said coupling elements acting to centre said one end of the rotor upon the drive shaft axis as the bearing assembly elements are moved to their operative position.

2. A fan as claimed in claim 1, wherein one coupling element has a portion formed as a part of a sphere centred on the axis and the other coupling element cooperating with said part spherical portion for supporting said one end of the rotor and transmitting drive thereto with the element of the bearing assembly in their operative position and for sliding movement of said coupling elements with respect to one another as the elements of the bearing assembly move between their operative and second positions with the rotor axis always intersecting the shaft axis at said centre.

3. A fan as claimed in claim 2, wherein both coupling elements have co-operating part-spherical surfaces in frictional engagement.

4. A fan as claimed in claim 3, including biassing means which with said bearing assembly elements in a operative position act axially upon the rotor to maintain the coupling elements in frictional engagement.

5. A fan as claimed in claim 4, wherein said biassing means acts on the second bearing element.

6. A fan as claimed in claim 1, wherein said second bearing assembly element is mounted on an arm which is articulated to said guide means to swing in a plane perpendicular to the shaft axis.

7. A fan as claimed in claim 1, including fixed means to locate the rotor upon disengagement of said bearing elements.

8. A fan as claimed in claim 1, wherein the first bearing assembly element comprises a projection on the rotor end with an axial end recess and the second bearing assembly element includes a pin engaging in the recess under endwise bias.

9. A fan as claimed in claim 8, wherein a ring surrounds the pin and supports the projection when upon movement of the second bearing element to its second position the pin disengages from the recess.

10. A fan comprising a drive shaft, a bladed cylindrical rotor, means mounting the rotor for rotation about an axis coincident with that of the drive shaft, means for transmitting drive from the shaft to one end of the rotor, and guide means cooperating with the rotor whereby on rotation thereof in a predetermined direction by the drive shaft air is induced to flow from one side of the rotor through the path of the rotating blades to the interior of the rotor and thence again through the path of the rotating blades to another side of the rotor; said mounting means and drive transmitting means including coupling elements respectively at the shaft and at said one end of the rotor which elements are capable of separation and re-assembly by manual manipulation and on re-assembly cooperate to centre said rotor end upon the axis and said mounting means including further a bearing at the other end of the rotor wherein said bearing is movable between an operative position aligned with the shaft axis and a second position laterally spaced therefrom for disengagement of the rotor from said bearing.

11. A fan as claimed in claim 10, wherein the coupling elements include part-spherical surfaces which with the bearing in operative position are held in interengagement by reason of endwise location of the rotor by said bearing.

12. A fan comprising a drive shaft, a bladed cylindrical rotor overhung on the drive shaft, means mounting the rotor for rotation about an axis coincident with that of the drive shaft, means for transmitting drive from the shaft to one end of the rotor, and guide means cooperating with the rotor whereby on rotation thereof in a predetermined direction by the drive shaft air is induced to flow from one side of the rotor through the path of the rotating blades to the interior of the rotor and thence again through the path of the rotating blades to another side of the rotor; said mounting means and drive transmitting means including coupling elements respectively at the shaft and at said one end of the rotor which elements are capable of separation and re-assembly by manual manipulation and on re-assembly co-operate to centre said rotor end upon the axis and wherein one coupling element is a tubular end portion of said shaft and the other coupling element comprises a tubular part on the end of the rotor which engages snugly over the shaft end portion and over a resilient retainer portion in frictional engagement within the shaft end portion.

13. A fan comprising a drive shaft, a bladed cylindrical rotor overhung on the drive shaft, means mounting the rotor for rotation about an axis coincident with that of the drive shaft, means for transmitting drive from the shaft to one end of the rotor, and guide means cooperating with the rotor whereby on rotation thereof in a predetermined direction by the drive shaft air is induced to flow from one side of the rotor through the path of the rotating blades to the interior of the rotor and thence again through the path of the rotating blades to another side of the rotor; said mounting means and drive transmitting means including coupling elements respectively at the shaft and at said one end of the rotor which elements are capable of separation and re-assernbly by manual manipulation and on re-assembly cooperate to centre said rotor end upon the axis and wherein the coupling elements are ferromagnetic discs engaging face-to-face, at least one disc being permanently magnetized, and one element having a conical projection received in a centring recess in the other element.

14. A fan comprising a drive shaft, a bladed cylindrical rotor overhung on the drive shaft, means mounting the rotor for rotation about an axis coincident with that of the drive shaft, means for transmitting drive from the shaft to one end of the rotor, and guide means cooperating with the rotor whereby on rotation thereof in a predetermined direction by the drive shaft air is induced to flow from one side of the rotor through the path of the rotating blades to the interior of the rotor and thence again through the path of the rotating blades to another side of the rotor; said mounting means and drive transmitting means including coupling elements respectively at the shaft and at said one end of the rotor which elements are capable of separation and re-assembly by manual manipulation and on re-assembly cooperate to centre said rotor end upon the axis and wherein the coupling element at the shaft includes a disc with a shoulder and the coupling element at the rotor includes an end ring, the disc and ring having cooperating means for snapping the ring into retaining engagement over the disc and into abutment with the shoulder.

References Cited UNITED STATES PATENTS 2,629,330 2/ 1953 Meline 103-87 2,882,077 4/1959 Marsh 230134 2,942,773 6/ 1960 Eck 230125 3,021,049 2/1962 Settle 230-134- 3,064,452 11/1962 Gast 645 DONLEY J. STOCKING, Primary Examiner.

H. F. RADUAZO, Assistant Examiner. 

1. A FAN COMPRISING A DRIVE SHAFT, A BLADED CYLINDRICAL ROTOR, MEANS MOUNTING THE ROTOR FOR ROTATION ABOUT AN AXIS COINCIDENT WITH THAT OF THE DRIVE SHAFT AND FOR TRANSMITTING DRIVE FROM THE SHAFT TO ONE END OF THE ROTOR, GUIDE MEANS CO-OPERATING WITH THE ROTOR WHEREBY ON ROTATION THEREOF IN A PREDETERMINED DIRECTION BY THE DRIVE SHAFT TO INDUCE A FLOW OF AIR FROM ONE SIDE OF THE ROTOR THROUGH THE PATH OF THE ROTATING BLADES TO THE INTERIOR OF THE ROTOR AND THENCE AGAIN THROUGH THE PATH OF THE ROTATION BLADES TO ANOTHER SIDE OF THE ROTOR, SAID MOUNTING SAID DRIVE TRANSMITTING MEANS INCLUDING COUPLING ELEMENTS RESPECTIVELY AT THE SHAFT AND AT SAID ONE END OF THE ROTOR AND A BEARING ASSEMBLY AT THE OTHER END OF THE ROTOR INCLUDING A FIRST ELEMENT ON SAID OTHER END OF THE ROTOR AND A SECOND ELEMENT MOUNTED FOR MOVEMENT WITH RESPECT TO THE GUIDE MEANS BETWEEN AN OPERATIVE POSITION ON SAID AXIS WHEREIN SAID ELEMENTS CO-OPERATE TO SUPPORT AND AXIALLY LOCATE THE ROTOR FOR ROTATION BY THE DRIVE SHAFT AND A SECOND POSITION LATERALLY SPACED FROM THE OPERATIVE POSITION WHEREIN THE FIRST ELEMENT AND SECOND ELEMENTS DISENGAGE, THE COUPLING ELEMENTS ACCOMMODATING MOVEMENT OF THE ROTOR CONSEQUENT UPON MOVEMENT OF THE BEARING ASSEMBLY ELEMENT BETWEEN SAID OPERATIVE AND SAID SECOND POSITION THEREOF AND BEING CAPABLE OF SEPARATION AND RE-ASSEMBLY ON MANUAL MANIPULATION OF THE ROTOR WITH THE BEARING ASSEMBLY ELEMENTS IN SAID SECOND POSITION, AND SAID COUPLING ELEMENTS ACTING TO CENTRE SAID ONE END OF THE ROTOR UPON THE DRIVE SHAFT AXIS AS THE BEARING ASSEMBLY ELEMENTS ARE MOVED TO THEIR OPERATIVE POSITION. 